Tire Flat Spotting
Tire Flat Spotting
What is it? Does it go Away?
It is not uncommon to leave your car parked for days or even weeks without moving the car. It is also not uncommon in colder climates to drive your car in the day, park it over night and have the temperatures drop significantly. In both of these situations, your tires could experience temporary “flat-spotting.” What is this and what causes it? What does it feel like and does it go away? Before we start, just to reassure you, it does go away with running of your tires and we will explain below.
Let’s start with what it is and what causes it. Your tires have many components and almost all tires now have a nylon cap internally just below the tread. When your tire sits, of course the portion on the ground is flat, not round, like the rest of the tire. When the nylon stays in this flat state for a long time, or sometimes when it transitions from a warm tire to a cold tire, it can take a “set” to this flat shape.
Now, let’s talk about how it feels and how it goes away. It feels like you would expect. As you drive and your tires rotate, the “flat spot” which really isn’t flat anymore, just not quite as round as the other parts of your tire, makes your tires and vehicle vibrate. You will likely feel it in the steering wheel and maybe in the car in general. The good thing is that as you drive, your tires rotate, obviously, and your tires warm up. Both of these actions will work the “set” out of the nylon cap meaning that the “flat spot” will go away and the vibration will diminish to normal levels. The amount of driving distance and time will vary, but achieving normal highway speeds for over 20 minutes will relax most flat spotting.
Tire Flat Spotting – How do I minimize it?
As we have stated above, typical tire flat spotting is not permanent, however, it could be a temporary annoyance. Fortunately, steps to minimize flat spotting are in line with good tire maintenance. You can minimize tire flat spotting by keeping your tires at placard pressure. We do not recommend that you inflate beyond placard pressure and certainly do not over-inflate. Also, for your tires and for your vehicle, regular operation and movement of your vehicle is recommended. For tire/vehicle storage, see the website section on tire storage.
What else is there to know about Flat Spotting?
There are two other types of flat spotting that are much less prevalent. First, if you lock your tires up in severe braking, you could “flat spot” the tread by wearing away a large amount of tread in one particular area. This would be visually apparent on the tire and would also create a vibration in the car. It can eventually go away, but would likely take a long time, thousands of miles. Modern vehicles with Anti-Lock Brakes rarely experience this type of flat spotting.
Second, if your tires have been subjected to long storage times while loaded and over-inflated and with fairly high temperatures, the tires could develop a “semi-permanent” flat spotting. This flat spotting will eventually go away, but it may take a good bit of driving. Tires should not be stored loaded and over-inflated while subjected to heat. This is well-understand meaning that this type of flat spotting is unlikely.
In all cases, if you experience vibration when driving and it does not diminish or go away, you should see a tire specialist and have your tires inspected. Persistent vehicle vibration, caused by tires or other suspension components, could be an indication of a more serious problem.
What if the vibration does not go away?
You should see a tire specialist. Persistent vehicle vibration, caused by tires or other suspension components, could be an indication of a more serious problem.
What recourse do I have for tire replacement if the vibration does not go away?
If the vibration does not go away, you can consult the Michelin Promise Plan and/or the Michelin Warranty. Tire replacement or pro-rated tire replacement could be covered.
Will over-inflating my tires help prevent flat spotting?
No, in general over-inflating your tires will not help flat spotting. In some cases it could make it worse. We recommend placard pressure and not higher.
I need to store my vehicle for several months, what should I do?
See Tire Storage at Michelinman.com. Keep your tires inflated to placard pressure, away from heat, and away from chemical exposure.
Do “Tire Cradles” help prevent flat spotting?
Theoretically, tire cradles help to keep a round shape for your tires and therefore help to prevent flat-spotting. The cradle curvature would have to match the tire curvature to be effective. Michelin does not have any data to verify that tire cradles help reduce flat spot. We do know that when you store your tires in a cradle or not, if they are over-inflated, exposed to chemicals or excessive heat, your tires are at risk of damage, including flat spotting.
What if I don’t like the daily annoyance? I park my car each night, wake up to a 15 minute drive with annoying vibration before I get a smooth ride. Can I get my money back?
We suggest that you check to see that you are at the proper placard inflation pressure. It is possible that you could get your money back as part of the Michelin Promise Plan. However, it is unlikely that you will find any tires with no temporary flat spotting if your daily drive involves warmer temperatures and you park your car overnight in cold ambient temperatures.
Mounting the spare:
- Align the holes on the spare with the bolts on the wheel and push the tire in as far as it will go.
- Replace lug nuts and tighten.
- Replace the opposite lug nuts (this ensures they are tightened evenly).
- Lower your car.
- Retighten each lug nut, then its opposite.
A few more tips:
- Carry a pair of sturdy gloves and a garbage bag in your trunk, in case the tire you're removing is covered in mud and a sturdy board to place your jack on in case the ground is soft, to avoid the jack sinking in.
- Check the inflation pressure of the spare tire before mounting. If this is not possible, once mounted, drive carefully at low speed until it can be checked.
- Visit the nearest service station and inflate the tire correctly.
- If you have a mini spare, make sure you stay within its speed and mileage requirements.
- Visit your garage to find a replacement tire.
- Where necessary, use light machine oil on the wheel nut threads to help their removal.
- Poorly tightened wheel nuts risk damaging the brake discs or wheel mounting system.
- Use a torque wrench to make sure you tighten the nuts correctly with the correct torque.
If you don't have a torque wrench get a tire specialist to check them as soon as possible. This will ensure the correct torque has been applied.
- Correctly tightened wheel nuts will also make it easy to remove them.
Make sure your tires are registered to receive direct notification in the event of a safety-related recall.